Internal rotation and equilibrium structure of the 2-methyl-2-nitropropane molecule from joint processing of gas phase electron diffraction data, vibrational and microwave spectroscopy data, and quantum chemical calculation results


如何引用文章

全文:

开放存取 开放存取
受限制的访问 ##reader.subscriptionAccessGranted##
受限制的访问 订阅存取

详细

The structure and internal rotation of the 2-methyl-2-nitropropane molecule is studied by electron diffraction and quantum chemical calculations with the use of microwave and vibrational spectroscopy data. The electron diffraction data are analyzed within the general intramolecular anharmonic force field model and the quantum chemical pseudoconformer model, considering the adiabatic separation of the degree of freedom of large amplitude motion, i.e., the internal rotation of the NO2 group. The equilibrium eclipsed configuration of the Cs symmetry molecule has the following experimental bond lengths and valence angles: re(N=O) = 1.226//1.226(8) Å, re(C–N)//re(C–C) = 1.520//1.515/1,521(4) Å, ∠еC–C–N = = 109.1/106,1(8)°, ∠еO=N=O = 124.2(6)°, ∠eC–C–Havg = 110(3)°. The equilibrium geometry parameters are well consistent with MP2/cc-pVTZ quantum chemical calculations and microwave spectroscopy data. The thermally average parameters previously obtained within the small vibration model show a satisfactory agreement with the new results. The electron diffraction data used in this work do not allow a reliable determination of the barrier to internal rotation. However, at a barrier of 203(2) cal/mol, which is derived from the microwave study, it follows from the electron diffraction data that the equilibrium configuration must correspond to an eclipsed arrangement of C–C and N=O bonds, which is also consistent with the results of quantum chemical calculations of various levels.

作者简介

Yu. Tarasov

Joint Institute for High Temperatures; Moscow Technological University

编辑信件的主要联系方式.
Email: tarasov@phys.chem.msu.ru
俄罗斯联邦, Moscow; Moscow

I. Kochikov

Moscow State University

Email: tarasov@phys.chem.msu.ru
俄罗斯联邦, Moscow

D. Kovtun

Joint Institute for High Temperatures; Moscow Technological University

Email: tarasov@phys.chem.msu.ru
俄罗斯联邦, Moscow; Moscow

E. Polenov

Moscow Technological University

Email: tarasov@phys.chem.msu.ru
俄罗斯联邦, Moscow

A. Ivanov

Moscow State University

Email: tarasov@phys.chem.msu.ru
俄罗斯联邦, Moscow

补充文件

附件文件
动作
1. JATS XML

版权所有 © Pleiades Publishing, Ltd., 2017